This invention relates to a golf club and a shaft therefor and particularly relates to a golf club and a shaft therefor having structure which increases the opportunity for making clubs of lighter weight with enhanced flexibility and torsional characteristics.
Golfing is a world wide sport with increasing popularity. With the increase in the golfing population, there is a significant increase in the number of players with a discerning demand for golf clubs which will improve and enhance their playing of the game. This demand goes well beyond those who play professionally and those in the upper levels of the amateurs.
Typically, some of the aspects of concern for the discerning golfer are the weight of the club, a balance between the flexibility and the stiffness of the shaft, and the torsional character of the shaft. Golfers usually prefer a light-weight club for obvious reasons. However, the flexibility and torsional requirements vary amongst golfers and relate to the golfer's "feel" of the club when the club is swung and upon impact with the ball.
In an effort to provide golf clubs which generally address the concerns noted above, many designs of shaft configuration and composition have evolved over the years. Some of these designs involve the placement of an enlargement in a selected portion of the shaft to, in effect, divide the shaft into two sections. One example of this premise regarding metal shafts is disclosed in U.S. Pat. No. 2,050,554 which issued on Aug. 11, 1936. An example of such structure in a composite or non-metallic shaft is disclosed in United Kingdom Patent No. GB 2,250,443 which issued on Aug. 24, 1994.
While golf clubs having shafts with a variety of such enlargement designs have been effective, there is a continuing demand and need for further improvement in this aspect of shaft design.
In addition, each club within a set of clubs typically has parameters which are different from the parameters of the other clubs in the set. For example, the club length, club weight, head configuration and other club parameters of each of the clubs of a set is different from the same parameters of the other clubs in the set. This equates to a different Moment-of-Inertia and different torsional requirement for each club with respect to each of the other clubs of the set. Therefore, each time the golfer uses a different club from the set in the normal playing of the game of golf, the golfer experiences different reactions from the swinging of the various clubs of the set which could affect the consistency in the golfer's playing of the game.
In view of this potential inconsistency, there is a need to balance or match the clubs of a set so that torsional stability of each club is normalized with respect to the other clubs of the set and the reaction realized by the golfer is somewhat consistent from club to club of the set.